Chapter 13 - The Heart - based on exam study guide PDF

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based on exam study guide...

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Location, characteristics, and functions of the heart ●

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Location - in the mediastinum (membrane enclosed space between the lungs) ○ 2 thirds are on the left side of the midline ○ Inferior margin is the apex - aligned with the midclavicular line ○ Superior margin is the base  ○ In the pericardial cavity - which provides protection and prevention from overstretching and staying inside mediastinum Characteristics ○ Cardiac muscles - desmosomes, gap junctions, and intercalated discs ○ Left pump is stronger

Markings of the heart surface (sulci)- coronary blood vessels + fat ● ● ●

Coronary - boundary between atria and ventricles Anterior interventricular - between ventricles Posterior interventricular - between ventricles at the back

Names and structure of the heart wall ● ● ●   

Epicardium - visceral layer of pericardium Myocardium - heart wall, cardiac muscle layer Endocardium

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Surface features and projections of the heart

Gross and internal anatomy both  atria and ventricles of the heart ●

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Right Atria ○ Forms right border ○ 2-3 mm thick ○ Receives all deoxygenated blood from vena cava and c  oronary sinus ○ Tricuspid valve ○ Pectinate muscles - smooth ridges on the wall ○ Fossa ovalis - key in fetal development, but then is just left as a fossa ○ Interventricular septum Left Atria ○ Receive from pulmonary veins Right Ventricle ○ 4-5 mm thick ○ Pulmonary valve and trunk ○ Interventricular septum ○ Chordinae tendinae, hold AV valves in place while the heart is pumping ○ Trabeculae carneae pull on chordae tendineae Left Ventricle ○ Thickest - pump into aorta

  -The purpose of the pulmonary and systemic circulations and blood vessels belong to each of these circulations

Valves ● ●

AV VALVE - Bicuspid (right side), Tricuspid (left side) SEMILUNAR - Aortic, pulmonary

Coronary circulation ●

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LEFT ○ Anterior interventricular artery - septum , and walls of both ventricles ○ Circumflex artery - left atrium and ventricle RIGHT ○ Marginal - wall of right margin of heart

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Posterior interventricular artery - walls of ventricles on back side

Conduction system -

During development 1% of cardiac fibers become autorhythmic cells that determine the pace and do not rely on the nervous system, Sa node, av node, bundle of his, purkinje fibers...